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| author |  Sebastian Andrzej Siewior <bigeasy@linutronix.de>
| 2024-03-01 22:45:22 +0100 |
|---|---|---|
| committer |  Greg Kroah-Hartman <gregkh@linuxfoundation.org>
| 2024-03-02 22:06:21 +0100 |
| commit | 6ba52968601ad3851d0b1da7dbe227b47a7dc918 (patch) | |
| tree | 8ad772f64c1613bd406f1ac7756aec32c9ac9f5c /drivers/tty/serial | |
| parent | serial: sunplus: Use uart_prepare_sysrq_char(). (diff) | |
| download | linux-6ba52968601ad3851d0b1da7dbe227b47a7dc918.tar.gz linux-6ba52968601ad3851d0b1da7dbe227b47a7dc918.tar.bz2 linux-6ba52968601ad3851d0b1da7dbe227b47a7dc918.zip | |
serial: lpc32xx_hs: Use uart_prepare_sysrq_char() to handle sysrq.
The port lock is a spinlock_t which is becomes a sleeping lock on PREEMPT_RT.
The driver splits the locking function into two parts: local_irq_save() and
uart_port_lock() and this breaks PREEMPT_RT.
Handle sysrq requests sysrq once the port lock is dropped.
Remove the special case in the console write routine an always use the
complete locking function.
Cc: Vladimir Zapolskiy <vz@mleia.com>
Cc: linux-arm-kernel@lists.infradead.org
Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de>
Link: https://lore.kernel.org/r/20240301215246.891055-10-bigeasy@linutronix.de
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Diffstat (limited to 'drivers/tty/serial')
| -rw-r--r-- | drivers/tty/serial/lpc32xx_hs.c | 17 |
1 files changed, 7 insertions, 10 deletions
diff --git a/drivers/tty/serial/lpc32xx_hs.c b/drivers/tty/serial/lpc32xx_hs.c index 269efc5e2d51..3e4ac46de1bc 100644 --- a/drivers/tty/serial/lpc32xx_hs.c +++ b/drivers/tty/serial/lpc32xx_hs.c @@ -136,20 +136,16 @@ static void lpc32xx_hsuart_console_write(struct console *co, const char *s, int locked = 1; touch_nmi_watchdog(); - local_irq_save(flags); - if (up->port.sysrq) - locked = 0; - else if (oops_in_progress) - locked = uart_port_trylock(&up->port); + if (oops_in_progress) + locked = uart_port_trylock_irqsave(&up->port, &flags); else - uart_port_lock(&up->port); + uart_port_lock_irqsave(&up->port, &flags); uart_console_write(&up->port, s, count, lpc32xx_hsuart_console_putchar); wait_for_xmit_empty(&up->port); if (locked) - uart_port_unlock(&up->port); - local_irq_restore(flags); + uart_port_unlock_irqrestore(&up->port, flags); } static int __init lpc32xx_hsuart_console_setup(struct console *co, @@ -266,7 +262,8 @@ static void __serial_lpc32xx_rx(struct uart_port *port) tty_insert_flip_char(tport, 0, TTY_FRAME); } - tty_insert_flip_char(tport, (tmp & 0xFF), flag); + if (!uart_prepare_sysrq_char(port, tmp & 0xff)) + tty_insert_flip_char(tport, (tmp & 0xFF), flag); tmp = readl(LPC32XX_HSUART_FIFO(port->membase)); } @@ -331,7 +328,7 @@ static irqreturn_t serial_lpc32xx_interrupt(int irq, void *dev_id) __serial_lpc32xx_tx(port); } - uart_port_unlock(port); + uart_unlock_and_check_sysrq(port); return IRQ_HANDLED; } |